Magnetically-operated locking and control device

ABSTRACT

A locking and control device has at least one tumbler in which a control magnet is arranged, and which is rotatable between two extreme positions. The tumbler is movable by means of an operating magnet carried by a functional member to an operative position in which a protection bolt can be inserted through an excision of the tumbler. A magnetic compensatory device comprises a further magnet carried by the functional member, with the compensatory magnet and the operating magnet arranged so that in the operative position they are located on either side of the control magnet but in a plane transposed along the axis of rotation of the tumbler. The compensatory device exerts a repulsive force contrary to the operating magnet, with the result that the control magnet is urged to said operative position which is intermediate said extreme positions. In a non-operative position the tumbler has a contacting surface disposed adjacent a contacting surface of the bolt, to prevent withdrawal of the latter, and the contacting surface of the tumbler is formed with at least one detent groove. The bolt can enter into detent engagement with said groove to prevent unauthorised rotation of the tumbler when in a position separate from the operative position, and the tumbler is associated with a security-type magnet arrangement which tends to shift the tumbler into the position of detent engagement.

United States Patent [191 Hallmann 4i MAGNETICALLY-OPERATED LOCKING AND CONTROL DEVICE [76] Inventor: Hermann Hallmann, Hofweg 51, 2

Hamburg 76, Germany [22] Filed: Feb. 8, 1973 [21] Appl. No.: 330,758

[30] Foreign Application Priority Data 4/1972 Heimann 70/276 Primary Examiner-Albert G. Craig, Jr. Attorney, Agent, or F irm-Beaman & Beaman [5 7] ABSTRACT A locking and control device has at least one tumbler Mar. 19, 1974 in which a control magnet is arranged, and which is rotatable between two extreme positions. The tumbler is movable by means of an operating magnet carried by a functional member to an operative position in which a protection bolt can be inserted through an excision of the tumbler. A magnetic compensatory device comprises a further magnet carried by the functional member, with the compensatory magnet and the operating magnetarranged so that in the operative position they are located on either side of the control magnet but in a plane transposed along the axis of rotation of the tumbler. The compensatory device exerts a repulsive force contrary to the operating magnet, with the result that the control magnet is urged to said operative position which is intermediate said extreme positions. In a non-operative position the tumbler has a contacting surface disposed adjacent a contacting surface of the bolt, to prevent withdrawal of the latter, and the contacting surface of the tumbler is formed with at least one detent groove The bolt can enter into detent engagement with said groove to prevent unauthorised rotation of the tumbler when in a position separate from the operative position, and the tumbler is associated with a security-type magnet arrangement which tends to shift the tumbler into the position of detent engagement.

5 Claims, 4 Drawing Figures PATENTEDHAR 1 9 1914 saw 1 OF 2 rill/I/II/A L MAGNETICALLY-QPERATED LOCKING AND CONTROL DEVICE BACKGROUND OF THE INVENTION The invention relates to a magnetically-operated locking and control device having at least one control magnet which is arranged to be movable between two extreme positions and which is capable of movement by means of at least one operating magnet into an operative position for the implementation of a control function, and with a magnetic compensatory device which exerts a repulsive force operating contrary to the control magnet in such manner that, upon the involvement of the operating magnet and because of the force of the latter which is likewise repulsive, the result is an intermediate position lying between the two extreme positions. The magnetic compensatory device is attached to the functional member carrying the operating magnet, the magnet of the compensatory device and the operatin g magnet being so arranged that in the operative position they are located on either side of the rotatably carried control magnet but in a plane transposed along the axis of rotation of the control magnet, and the control magnet is arranged in at least one tumbler which is provided with an excision for the insertion therethrough of a protective bolt while in the operative position and which is adjacent to a contacting surface on the protective bolt while in the non-operative position.

Such a locking and control device is described in the specification of co-pending Application Ser. No. 205,654 as one of two exemplaryv embodiments. In this device the tumbler and the protective bolt in the nonoperative position are pressedresiliently against each other, with the consequence that the tumbler is retained in place by frictional contact. If the functional member (the magnetic key) carrying the operating and the compensatory magnets is placed under pressure, then the contacting surface on the tumbler lifts from the protective bolt. The tumbler is then able to rotate freely under the influence of the magneticforces to which it is subjected. The magnets of the functional member co-act wit-h the control magnet borne by the tumbler, which latter magnetmay consist merely of a piece of ferromagnetic material, in order to bring the tumbler to a free floatingstate (as determined by the resulting magnetic forces) in which the excision in the tumbler is aligned with the protective bolt. This excision provides clearance which allows relative displacement of the protective bolt and the tumbler. In this manner a control member connected to the tumbler or connected to a component carrying the tumbler undergoes displacement, during which it carries out a given control function (for example, it closes or releases a lock).

In the practical evaluation of such a locking and control device it has been shown that the device can also be actuated, by the display of great skill and of corresponding carefulness, even when in actuating magnet diverging from the prescribed form of magnet is employed. In fact, it is possible for the tumbler to be rotated from the non-operative position (which in general is determined by magnetic forces) into some desired other position by the use of any desired magnet, and on relieving the pressure exerted on the tumbler the latter is then retained in this position by frictional contact. If the tumbler is once more permitted to return to the non-operative position, then in this movement it moves through the operative position (the releasing position) in which the protective bolt can be inserted through the excision in the tumbler. If this return movement of the tumbler is carried out with great care and sensitive control of the pressure exerted on the tumbler then, given great skill, success can be achieved in bringing the tumbler into the operative position (the releasing position). This is possible even when the device uses a plurality of tumblers (for example, four tumblers) since, because of manufacturing tolerances in the axial play of the tumblers, these can be shifted in succession into the operative position permitting release.

SUMNIARY OF THE INVENTION It is an object of the present invention to provide a locking and control device of the foregoing general character constructed in such manner that unauthorised actuation of the locking and control device through the agency of an incorrect magnet is in practice ruled out.

This is achieved according to the invention by the fact that in the contacting surface of the tumbler at least one detent grooveis formed by means of which, to prevent any impermissible rotation, the tumbler may be heldin detent engagement with the protective bolt in positions apart from the operative position. In addition, the tumbler is associated with a security-type magnet arrangement which tends to shift the tumbler into 30 3 the position of detent.

In the second exemplary embodiment described in said specification of Application Ser. No. 205,654 a further magnet arrangement has already also been provided, in addition to the operating, control and compensatory magnets respectively. In this case the additional magnet arrangement, however, merely serves to fix the two extreme positions (the non-operative positions) of the tumbler, which is formed as a rocker unit. This fixing of the extreme positions of the tumbler is preferably employed in devices in accordance with the invention of Application Ser. No. 205,654 which is further developed by the present invention by the control magnet itself, which for example co-operates 'with the control magnet of a second tumbler. The

security-type magnet arrangement. provided in accordance with the invention does not serve, however, to fix the extreme positions of the tumbler but, rather, to prestress the tumbler in the direction to bring the additionally provided detent groove to an operative position.

The detent groove provided according to the invention is formed in the contacting surface of the tumbler, as is the excision for the protective boltyit is, in contradistinction to the excision, preferably only a few tenths of a millimetre deep, and it has the effect that, given detent engagement between the tumbler and the protective bolt, the control member is not operated. If the tumbler, actuated by means of a foreign magnet, is rotated into any position and is held in that position by frictional contact, and if then the attempt is made to turnit to the releasing position by varying the pressure exerted on the tumbler, the security magnet arrangeresult it is prevented from further rotation. In order to be able to rotate the tumbler again at all, the tumbler has to be completely lifted from the protective bolt by externally exerted pressure, whereupon the tumbler, having meanwhile undergone displacement, once more returns to the final locking position. As has been ascertained in numerous tests, the locking and control device formed according to the invention can certainly not be actuated either by foreign magnets or by any application of force (e.g. drilling).

It will be appreciated that the magnetic force of the security magnet arrangement provided according to the invention is large enough to shift the tumbler reliably into the position of detent, but is not so large that it will unfavourably affect the actuation of the locking and control device by means of the correct operating and the compensatory magnets respectively.

BRIEF DESCRIPTION OF THE DRAWINGS A locking and control device which is a preferred embodiment of the invention will now be described in detail, by way of example, with reference to the accompanying drawings, in which:-

FIG. 1 is a sectional view through the locking and control device,

FIG. 2 is a detail sectional view on the line ll II in FIG. 1,

FIG. 3 is a sectional view on. the line III III in FIG.

1 and FIG. 4 is a sectional view on the line IV IV in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The locking and control device illustrated in the drawings has a cylindrical housing 1 in which a cylindrical pressure-subject member 2 is arranged so as to be movable axially.

The member 2 is closed at its lower end by a pressure plate 3 on which to approximately cylindrical rotors 4 and 5 are rotatably positioned with axial play on supporting pins 6,7. Each of the rotors 4,5 has at its upper, front end a control magnet 8 and 9 respectively (see particularly FIG. 3). Each of the rotors 4,5 is further provided with an annular groove, 10 and 11 respectively, by means of which an annular shoulder, 12 and 13 respectively, is formed to act as a contacting surface. An annular collar 14 of a protective bolt 15, which is fastened by means of a screw 16 to the housing 1, penetrates into the annular grooves 10,1 1. The member 2 is resiliently urged upwardly by a coil spring 17, with the consequence that the rotors 4,5 have their contacting surfaces 12,13 while in the non-operative position (the releasing position) pressed against the annular collar 14 on the protective bolt 15. The two ro tors 4,5 are each further provided with an excised portion, 24 and 25 respectively, extending in the axial direction.

In order to rotate the rotors 4,5 a functional member in the form of a magnetic key 26 is provided, this having in respect of each control magnet 8 or 9 of the two rotors two magnets 27,28 and 29,30 respectively. Of the two magnets 27,28 and 29,30 respectively, one of each pair functions as the operating magnet and one as the compensatory magnet which, when the magnetic key is applied (when the magnetic key is placed on the member 2), exert contrary forces on the pertinent control magnet 8 or 9 respectively, with the consequence that the control magnet and the rotor associated with it adopt a floating state conditioned alone by magnetic forces. In this floating state, which functions as the operative position (the releasing position), the excisions 24 and 25 complement each other to form an aperture through which the annular collar 14 of the protective bolt 15 can be introduced (FIG. 3).

The locking and control device as described so far is substantially as disclosed in the aforesaid specification of Application Ser. No. 205,654. In order to operate the device, the magnetic key 26 is placed on the member 2 and is pressed downwardly against the force of the spring 17, with the consequence that the annular collar 14 and the contacting surfaces 12,13 of the two rotors lift apart. The two rotors are then under the influence of the magnets 8, 9, 27, 28, 29 and 30, rotated to their releasing positions in which the annular collar 14 on the protective bolt 15 is able to move freely through the excisions 24,25 in the rotors. The entire member 2 therefore springs upwardly under the effect of the urging of the spring 17. A control member connected with pressure-subject member 2 (this control member is, for instance, a protective bolt for a lock) consequently undergoes displacement in order to perform a control function (the locking or release of th lock).

As has already been mentioned initially, a locking and control device merely formed in the manner as so far described can, given the application of the appropriate skill, also be actuated by means of a foreign magnet. For this purpose, the rotors 4,5 are rotated by the foreign magnet (after the pressure-subject member 2 has been pressed down) from the locked position shown in broken lines in FIG. 3 into any desired other position. On easing of the pressure exerted on the member 2, the contacting surface 12 or 13 of the rotor 4 or 5 respectively is pressed against the annular collar 14 of the protective bolt 15, with the consequence that the rotors are retained in their position. By skilful variation of the pressure exerted on the member 2 successful actuation can then be achieved, with a device as described in said specification, in moving the rotors to the positions permitting release.

In order to prevent such unauthorised actuation, in each of the contacting surfaces 12,13 of the present device there are formed detent grooves 18 and 18, respectively, in the form of sector-shaped recesses (FIG. 2). The detent grooves are only a few tenths of a millimetre deep, and the protective edges delimiting the detent grooves run substantially around the entire area of the annular shoulder that is not cut away by the excision 24.

Further, on the lower rear-end of each of the rotors 4 and 5 and in fact at a location diametrically opposite the excisions 24 and 25 respectively there are arranged magnets 20 and 21, respectively. With each of the magnets 20,21 there is associated a magnet, 22 or 23, positioned in the pressure-plate 3. The positioning of the magnets 22,23 is so selected that in the releasing position they are axially oppositethe magnet 20,21 of the rotors 4 and 5, respectively, and hence exert a repulsive force on each rotor.

If, for example, the rotor 4 is located in the releasing position without it also being retained in this position by the appropriate magnetic key 26, then the rotor 4 is not merely raised in the axial direction from the pressure-plate 3 by the repulsion forces of the magnets 20 and 22; rather, the rotor attempts evasive movement as well, and is rotated so that it jumps behind the protective edge of the corresponding detent groove 18 or 18'. The releasing position (with the magnetic key removed) is therefore an unstable position from which the rotor attempts to escape. 7

If, therefore, the rotor is rotated by a foreign magnet into some position and thereupon the pressure on the pressure-subject cylinder 2 is decreased, then in practice it is impossible for the rotor to attain the releasing position. Rather, the magnets 20 and 22, repelling each other and capable of effecting rotation of the rotor through up to 180, impel the rotor to jump into its position of detent engagement, in which the annular collar 14 on the protective bolt 15 penetrates the detent groove and prevents any further rotation of the rotor. In order now to free the rotor from the position of detent engagement, it is necessary to press the pressuresubject member 2 fully down, whereupon the rotor once more springs into its final locking position. It is therefore in practice impossible to actuate the locking and control device by means of a foreign magnet.

I claim:

1. A magnetically-operated locking and control device with at least one control magnet which is arranged to be movable between two extreme positions and is capable of movement by means of at least one operating magnet into an operative position for the implementation of a control function, and with a magnetic compensatory device which exerts a repulsive force operating contrary to the controlmagnet in such a manner that, upon the involvement of the operating magnet, because of the force of the latter which is likewise repulsive, the result is an intermediate position of the control magnet lying between the two extreme posi-- tions, the magnetic compensatory device being attached to the functional member carrying the operating magnet with the magnet of the compensatory device and the operating magnet so arranged that in the operative position they are located on either side of the rotatably borne control magnet but in a plane transposed along the axis of rotation of the control magnet, the control magnet being arranged in at least one tumbler which is provided with an excision through which a protective bolt can be inserted while the tumbler is in the operative position and which is adjacent to a contacting surface on the protective bolt while in the nonoperative position, wherein the corresponding contacting surface of the tumbler is formed with at least one detent groove by means of which, to prevent unauthorised rotation, the tumbler may be held in detent engagement with the protective bolt in a position or positions separate from the operative position, and wherein the tumbler is associated with a security-type magnet arrangement which tends to shift the tumbler into the position of detent engagement.

2. A device according to claim 1, wherein the detent groove consists of a flat, sector-shaped recess in the corresponding contacting surface.

3. A device according to claim 2, wherein the protective edge of the recess extends up to the immediate vicinity of the excision for insertion of the protective bolt.

4. A device according to claim. 1, with a pressuresubject member mounted so as to be movable axially in a housing and resiliently urged in one direction, in which member the tumbler is rotatably carried with axial play and so as to be retained in the non-operative position, against the urging of a spring, by the contact of the protective bolt against the contacting surface of the tumbler in such manner that the tumbler lifts from the protective bolt as a result of the pressure-subject member being pressed down by means of the functional member and is tumed by the operating magnet and the compensatory 'magnet into its operative position, wherein the security-type magnet arrangement comprises two magnets which repel each other, these magnets being fastened in the facing surfaces of the tumbler and of the pressure-subject member, respectively, and associated with each other in such manner that in the operative position of the tumbler they exert a maximum repulsive force on each other.

5. A device according to claim 4, wherein the magnet fastened on the tumbler is diametrically opposite the excision in the tumbler. 

1. A magnetically-operated locking and control device with at least one control magnet which is arranged to be movable between two extreme positions and is capable of movement by means of at least one operating magnet into an operative position for the implementation of a control function, and with a magnetic compensatory device which exerts a repulsive force operating contrary to the control magnet in such a manner that, upon the involvement of the operating magnet, because of the force of the latter which is likewise repulsive, the result is an intermediate position of the control magnet lying between the two extreme positions, the magnetic compensatory device being attached to the functional member carrying the operating magnet with the magnet of the compensatory device and the operating magnet so arranged that in the operative position they are located on either side of the rotatably borne control magnet but in a plane transposed along the axis of rotation of the control magnet, the control magnet being arranged in at least one tumbler which is provided with an excision through which a protective bolt can be inserted while the tumbler is in the operative position and which is adjacent to a contacting surface on the protective bolt while in the non-operative position, wherein the corresponding contacting surface of the tumbler is formed with at least one detent groove by means of which, to prevent unauthorised rotation, the tumbler may be held in detent engagement with the protective bolt in a position or positions separate from the operative position, and wherein the tumbler is associated with a security-type magnet arrangement which tends to shift the tumbler into the position of detent engagement.
 2. A device according to claim 1, wherein the detent groove consists of a flat, sector-shaped recess in the corresponding contacting surface.
 3. A device according to claim 2, wherein the protective edge of the recess extends up to the immediate vicinity of the excision for insertion of the protective bolt.
 4. A device according to claim 1, with a pressure-subject member mounted so as to be movable axially in a housing and resiliently urged in one direction, in which member the tumbler is rotatably carried with axial play and so as to be retained in the non-operative position, against the urging of a spring, by the contact of the protective bolt against the contacting surface of the tumbler in such manner that the tumbler lifts from the protective bolt as a result of the pressure-subject member being pressed down by means of the functional member and is turned by the operating magnet and the compensatory magnet into its operative position, wherein the security-type magnet arrangement comprises two magnets which repel each other, these magnets being fastened in the facing surfaces of the tumbler and of the pressure-subject member, respectively, and associated with each other in such manner that in the operative position of the tumbler they exert a maximum repulsive force on each other.
 5. A device according to claim 4, wherein the magnet fastened on the tumbler is diametrically opposite the excision in the tumbler. 